1. Field of the Invention
The present invention generally relates to charging apparatus and particularly relates to a charging apparatus capable of reducing the power loss due to charging.
2. Description of Related Art
A secondary battery is widely used for various applications. The capacity of a secondary battery used in a mobile phone, for example, significantly increases recently, and the charging current increases accordingly in order to reduce charge time and increase user-friendliness. Though the power loss is inevitable for a charging circuit, an increase in the charging current results in an increase in the power loss in the charging circuit, which is a product of the charging current I and the voltage drop V in the charging circuit, and the heating becomes not negligible. The heating causes heat dissipation and other various adverse effects upon selection and mounting of a component and so on.
Description on a charging circuit can be found in Japanese Unexamined Patent Publications No. 2003-111292 and 2004-364393, for example. Neither of them, however, deals with the issue of heating in the charging circuit.